By Matthew Davis
Rising like a wall out of the inhospitable desert, the Gilf al-Kebir ("Great Barrier") is an isolated, unvisited place in comparison with Egypt's famous monuments and Red Sea beaches.
Gilf al-Kebir: "Damned remote"
Just a few thousand "adventure tourists" venture there each year - to Egypt's south-western border with Libya and Sudan - following in the tracks of desert explorers, Bedouin nomads, Second World War battle groups and fictional archaeologists.
But the kidnapping of a group of Western tourists in the area has turned the spotlight firmly on an edgy area steeped in ancient legend.
The giant upland - the size of Switzerland - is about as Indiana Jones as it gets on a guided tour.
It is home to the scattered remains of ancient Egypt, to prehistoric paintings like those in the "Cave of Swimmers" and - mythically - to the lost Oasis of Zerzura, where riches await whoever seizes the key to a legendary city.
Sparsely-populated, and thinly policed, it is also a rare weak spot for Egyptian security.
The area is close to conflict zones in Darfur in western Sudan, and in eastern Chad. Tour operators say nomads from all the border countries roam the area.
Despite a number of high-profile militant attacks in Egypt in recent years, banditry in tourist areas is uncommon.
But in remote places, far from the reach of the country's security forces, robberies and kidnappings do occur and are difficult to guard against.
A typical "explorer tour" of the region - whether by 4x4 or camel - begins with a long coach journey from Cairo, to a town on the eastern edge of the "Sea of Sand" that extends into the Libyan Desert.
Venturing towards the Gilf al-Kebir, groups will strike periodic camps, staying under canvas for a couple of nights at a time while exploring the variety of wadis, caves and passes that hide the plateau's treasures.
Those approaching the south-eastern flank will most likely visit the Eight Bells, a series of hills nearby which is an old Second World War airfield - where partially-buried petrol cans still indicate wartime runways.
The rusting shells of wartime vehicles are constantly rediscovered. Only last year a bag of personal effects lost by a dispatch rider was found by a guide in the area, and reunited with the soldier's family in the UK.
Zarzura is said to have been a whitewashed city of the desert, on whose gate was carved a tiny bird. In the beak of the bird was a key to the city, and the untold riches therein
Most of the region's history - from prehistoric settlements, to silica glass fields - is much more ancient, however.
Wadi Sora (The Valley of the Pictures) is home to a myriad of cave paintings, chief among them those of swimming figures - documented in 1929 by the Hungarian aristocrat and desert explorer Laszlo Almasy. They point to a time when the area was not simply arid desert.
Count Almasy - and the "Cave of Swimmers" - were immortalised in the 1996 film version of Michael Ondaatje's novel, The English Patient.
One location not on any itinerary, but among the chief mythologies of the region, is the lost Oasis of Zarzura.
Zarzura is said to have been a whitewashed city of the desert, on whose gate was carved a tiny bird. In the beak of the bird was a key to the city, and to the untold riches therein.
At the southern end of the plateau is the mountain range of Jebel Uweinat, effectively an area of no-man's land between the Sudanese, Libyan and Egyptian borders.
Here, the jurisdiction of national authorities blurs, and is ill defined.
The Lonely Planet guidebook to Egypt barely mentions the region. One of the book's authors described the area to the BBC simply as "damned remote".